Danica Patrick had to go to a backup car early at Bristol after tagging the wall in the first practice. / Mike Dinovo, USA TODAY Sports

by Nate Ryan, USA TODAY Sports

by Nate Ryan, USA TODAY Sports

BRISTOL, Tenn. â?? Group qualifying might have been tweaked with safety enhancements, but Bristol Motor Speedway still was a precarious place Friday for NASCAR's premier series.

Kyle Busch, Greg Biffle, Danica Patrick, Parker Kligerman and Justin Allgaier all sustained damage during incidents within the first 45 minutes of Sprint Cup practice for Sunday's Food City 500.

Busch, Biffle and Patrick needed backup cars. Each driver lost control while coming off a turn on the 0.533-mile oval, tagging the wall with the right rear.

In an interview on Fox Sports 1, Denny Hamlin said the crashes were the result of drivers trying to get a handle on new 2014 rules (such as no minimum front-end height) and a new tire compound that combined to produce higher speeds.

"I really don't think (the track is) treacherous," said Hamlin, whose Joe Gibbs Racing team sat out the first 15 minutes of the session while waiting for the grip level to build. "It's just the speeds are so much higher than we've seen. It takes a little getting used to. We are all out there fighting for a tenth-of-a-second -- a hundredth-of-a-second at Bristol. I think it comes more from us pushing the edge than it is treacherous."

Ricky Stenhouse Jr. also scraped the wall late in practice with his No. 17 Ford, but the minor damage didn't seem to necessitate a backup.

Kurt Busch paced the practice with a 129.789-mph lap (bettering the track record of 129.535 mph set last year by his younger brother, Kyle). Jeff Gordon was second, then Hamlin, Carl Edwards and Marcos Ambrose.

Bristol has been reconfigured twice since 2007, and the latest overhaul pushed the preferred groove to the high line around the track, putting cars inches from the wall for average laps at 125 mph.

Matt Kenseth, who won at Bristol last August, narrowly averted scraping the right rear of his No. 20 Toyota along the wall while sliding off a turn. He scraped it late in the session, but the damage seemed repairable.

"It's a challenging track," Kenseth said before practice. "I always like coming here no matter what the configuration is. It's changed a lot over the years. It definitely changes a lot during the weekend. I think the track is going to be drastically different here in a little while, and it probably will again in qualifying later this afternoon, and it will be in the race again. You always have to pay attention to that."

The higher speeds also could factor into group qualifying, which will make its debut at Bristol under new rules from NASCAR. After drivers voiced complaints about the dangers of cooling engines on the track during the first two sessions at Phoenix and Las Vegas, teams will be allowed to use cooldown units in the pits at Bristol.

Cooldown laps also won't be permitted, which Kenseth said should make group qualifying "less chaotic and confusing hopefully. I think it's going to look more like a normal qualifying session except there will be more cars out there. Everybody should be able to be more patient and pick and choose your time when you want to get rolling. Be able to wait for a clean lap and go."

Six-time champion Jimmie Johnson said Bristol qualifying would have been "total chaos" without the changes.

"We have had two very forgiving racetracks with generous aprons to cool down on and we still had some close calls," he said. "Here you can't get on the apron to get out of the way. I think we will see a much cleaner, fair opportunity to get your fast laps in."